Radio communication systems are well known in the art. Further, programmable radios are often used in such communication systems to provide flexible adaptation of communication features. Unlike radios of the past that relied on hardware components to establish radio functionality, today's features are provided through the use of software and firmware residing in the radio. This allows for flexible feature programming without the need to disassemble the radio unit and add (or replace) hardware components each time an upgrade is desired.
FIG. 1 shows an exemplary radio programming system 100 that includes a programmable radio 102, a programming source 104, and a programming link 106. Generally, communication features are installed in the radio 102 by sending commands from the programming source 104, which commands include appropriate data for the features being programmed. This programming process is typically performed only by authorized service personnel, and therefore requires that the radio 102 be temporarily put out of service. Aside from the inconvenience of this, prior art programming techniques can be cost prohibitive. Perhaps even more importantly, today's programming methods include security provisions that can be readily compromised. That is, by illicit programming of legitimately owned radios, an unscrupulous party can upgrade a radio without paying the fees normally associated with that upgrade. Lastly, certain feature programming implementations are impractical in view of the size limitations put on the radio units. As an example, so called smartcards--i.e., credit card sized memory devices--can be used to directly provide operating features for the radio.
There are several problems with the programming techniques of the prior art, such as those generally depicted in FIG. 1. For example, a so-called hard key 108 provides security through the use of a hard-coded security code that is read by the programming source 104. However, the hard key 108 can be easily replaced with a hard key having a known security code. The software in programming source 104--typically a personal computer or the like--can then be modified to look for the known security code in the replaced hard key, rather than the original security code from the legitimate key. In this manner, an unscrupulous owner is able to program the radio 102 by simply modifying a few lines of programming code. This becomes an increasingly problematic security concern, as many radio owners are well versed in the programming languages used to modify radio features.
Use of a 110 is impractical for reasons having to do more with size limitations than with security (though security can also be a problem). In particular, today's card readers consume an inordinate amount of current when reading the smartcard 110. Accordingly, in applications where the portable radio 102 is size-limited, an oversized battery--to source the required current to the card reading hardware--would compromise the objective of making the radio smaller.
Accordingly, there exists a need for a radio programming system that is not constrained by the shortcomings of the prior art. In particular, such a system that did not rely on easily compromised hard keys for security, or current consuming smartcard readers, would be an improvement over the prior art.